Study: Conceiving in Summer Lowers Baby's Future Test Scores

If you follow astrology, the month when you are born says a lot about your personality, temperament and chances for love. Now, a group of researchers have found that the time of year a child is conceived may affect his or her future academic performance.

Dr. Paul Winchester, a neonatologist at the Indiana University School of Medicine and director of the Neonatal Intensive Care Unit at St. Francis Hospital in Indianapolis, studied the test scores of 1,667,391 Indiana students in grades 3 through 10.

Looking at the Indiana Statewide Testing for Educational Progress (ISTEP) exam, Winchester and his researchers found scores for math and language were clearly seasonal, with the lowest scores going to children conceived in June through August.

Winchester presented these findings on Monday's annual meeting of the Pediatric Academic Societies.

For the females in the study the difference was a 1 to 1.5 percent drop, and the results were similar for all groups and sexes conceived in May through August. Winchester noted that even though "it might not sound like a large number, it is significant on a population basis."

How could a baby conceived in the long days of summer test so differently? Researchers reasoned that the culprit is the more than one billion pounds of pesticides used annually in the U.S.

"The fetal brain begins developing soon after conception. The pesticides we use to control pests in fields and our homes and the nitrates we use to fertilize crops and even our lawns are at their highest level in the summer," Winchester said in a news release.

According to the American Pregnancy Association, even household gardening pesticides are well-known to put pregnant women at high risk for many birth defects, including oral clefts, neural tube defects, heart defects, and limb defects.

While domestic pesticides are the fastest growing segment of the pesticide industry, a correlation exists between all pesticide exposure and birth defects.

"We actually found that every single birth defect category had a greater risk between April and July," Winchester said. "It suggests that with seasonal factors, something is conferring increased risk."

And it is not just risk for birth defects; Winchester presented a study at the 2006 meeting of the Pediatric Academic Societies that the number two cause of infant mortality in the U.S., premature birth, also peaks along with pesticide use.

The evidence in this latest study shows that the trend in pesticide exposure, especially pesticides found in drinking water, is related to trends in test scores many years down the road.

"We have now linked higher pesticide and nitrate exposure in surface water with lower cognitive scores," Winchester said. "Neurodevelopmental consequences of exposure to pesticides and nitrates may not be obvious for many decades."

For pregnant mothers that cannot hide themselves away from a world of chemicals for nine months, the American Pregnancy Association offers these tips for handling pesticides around the house:

•Have someone else, preferably a professional, apply the pesticides

•Leave the area for the amount of time indicated on the pesticide package

•Remove food, dishes, and utensils from the area before the pesticide is used

•Wash the area where food is normally prepared following any application of pesticides in the home

•Open the windows and allow the house to ventilate after the treatment is completed

•Wear protective clothing when gardening to prevent contact with plants that have pesticide on them.

It may never be possible to completely avoid exposure to pesticides, but there is opportunity to introduce greater regulation.

"What I would like to see is large constituencies asking legislators and health officials to ask the questions in a better way," Winchester suggested. "Drinking water in 16 states in the U.S. is contaminated with pesticides during June, yet many water providers don't even send samples in June."

Next Winchester will study children with learning disabilities and their conception date to see if there is another correlation. So far, he says no matter what area of development he looks at, "the answer to my question is always the same, June."